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+/*
+ * Linux/PA-RISC Project (http://www.parisc-linux.org/)
+ *
+ * Floating-point emulation code
+ * Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+/*
+ * BEGIN_DESC
+ *
+ * File:
+ * @(#) pa/spmath/dfcmp.c $Revision: 1.1 $
+ *
+ * Purpose:
+ * dbl_cmp: compare two values
+ *
+ * External Interfaces:
+ * dbl_fcmp(leftptr, rightptr, cond, status)
+ *
+ * Internal Interfaces:
+ *
+ * Theory:
+ * <<please update with a overview of the operation of this file>>
+ *
+ * END_DESC
+*/
+
+
+
+#include "float.h"
+#include "dbl_float.h"
+
+/*
+ * dbl_cmp: compare two values
+ */
+int
+dbl_fcmp (dbl_floating_point * leftptr, dbl_floating_point * rightptr,
+ unsigned int cond, unsigned int *status)
+
+ /* The predicate to be tested */
+
+ {
+ register unsigned int leftp1, leftp2, rightp1, rightp2;
+ register int xorresult;
+
+ /* Create local copies of the numbers */
+ Dbl_copyfromptr(leftptr,leftp1,leftp2);
+ Dbl_copyfromptr(rightptr,rightp1,rightp2);
+ /*
+ * Test for NaN
+ */
+ if( (Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT)
+ || (Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT) )
+ {
+ /* Check if a NaN is involved. Signal an invalid exception when
+ * comparing a signaling NaN or when comparing quiet NaNs and the
+ * low bit of the condition is set */
+ if( ((Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT)
+ && Dbl_isnotzero_mantissa(leftp1,leftp2)
+ && (Exception(cond) || Dbl_isone_signaling(leftp1)))
+ ||
+ ((Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT)
+ && Dbl_isnotzero_mantissa(rightp1,rightp2)
+ && (Exception(cond) || Dbl_isone_signaling(rightp1))) )
+ {
+ if( Is_invalidtrap_enabled() ) {
+ Set_status_cbit(Unordered(cond));
+ return(INVALIDEXCEPTION);
+ }
+ else Set_invalidflag();
+ Set_status_cbit(Unordered(cond));
+ return(NOEXCEPTION);
+ }
+ /* All the exceptional conditions are handled, now special case
+ NaN compares */
+ else if( ((Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT)
+ && Dbl_isnotzero_mantissa(leftp1,leftp2))
+ ||
+ ((Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT)
+ && Dbl_isnotzero_mantissa(rightp1,rightp2)) )
+ {
+ /* NaNs always compare unordered. */
+ Set_status_cbit(Unordered(cond));
+ return(NOEXCEPTION);
+ }
+ /* infinities will drop down to the normal compare mechanisms */
+ }
+ /* First compare for unequal signs => less or greater or
+ * special equal case */
+ Dbl_xortointp1(leftp1,rightp1,xorresult);
+ if( xorresult < 0 )
+ {
+ /* left negative => less, left positive => greater.
+ * equal is possible if both operands are zeros. */
+ if( Dbl_iszero_exponentmantissa(leftp1,leftp2)
+ && Dbl_iszero_exponentmantissa(rightp1,rightp2) )
+ {
+ Set_status_cbit(Equal(cond));
+ }
+ else if( Dbl_isone_sign(leftp1) )
+ {
+ Set_status_cbit(Lessthan(cond));
+ }
+ else
+ {
+ Set_status_cbit(Greaterthan(cond));
+ }
+ }
+ /* Signs are the same. Treat negative numbers separately
+ * from the positives because of the reversed sense. */
+ else if(Dbl_isequal(leftp1,leftp2,rightp1,rightp2))
+ {
+ Set_status_cbit(Equal(cond));
+ }
+ else if( Dbl_iszero_sign(leftp1) )
+ {
+ /* Positive compare */
+ if( Dbl_allp1(leftp1) < Dbl_allp1(rightp1) )
+ {
+ Set_status_cbit(Lessthan(cond));
+ }
+ else if( Dbl_allp1(leftp1) > Dbl_allp1(rightp1) )
+ {
+ Set_status_cbit(Greaterthan(cond));
+ }
+ else
+ {
+ /* Equal first parts. Now we must use unsigned compares to
+ * resolve the two possibilities. */
+ if( Dbl_allp2(leftp2) < Dbl_allp2(rightp2) )
+ {
+ Set_status_cbit(Lessthan(cond));
+ }
+ else
+ {
+ Set_status_cbit(Greaterthan(cond));
+ }
+ }
+ }
+ else
+ {
+ /* Negative compare. Signed or unsigned compares
+ * both work the same. That distinction is only
+ * important when the sign bits differ. */
+ if( Dbl_allp1(leftp1) > Dbl_allp1(rightp1) )
+ {
+ Set_status_cbit(Lessthan(cond));
+ }
+ else if( Dbl_allp1(leftp1) < Dbl_allp1(rightp1) )
+ {
+ Set_status_cbit(Greaterthan(cond));
+ }
+ else
+ {
+ /* Equal first parts. Now we must use unsigned compares to
+ * resolve the two possibilities. */
+ if( Dbl_allp2(leftp2) > Dbl_allp2(rightp2) )
+ {
+ Set_status_cbit(Lessthan(cond));
+ }
+ else
+ {
+ Set_status_cbit(Greaterthan(cond));
+ }
+ }
+ }
+ return(NOEXCEPTION);
+ }